1. Field of the Invention
The invention pertains to an alarm system for a card or document holder pocket, more specifically to a self-contained portable alarm system having a unitary ribbon which is folded over the edge of a pocket opening and folded within the pocket and which gives alarm when the card or document is removed.
2. Description of the Prior Art
The prior art is replete with patented designs for card holder alarm systems that signal a warning when a card such as a credit card is removed from a wallet pocket.
U.S. Pat. No. 3,959,789 patented by F. M. McGahee on May 25, 1976 describes a check or credit card monitor consisting of a case having an alarm circuit, time delay circuit, power supply, and a cover having a plurality of separators adapted to hold documents between them. Each separator has an electrical contact. The separators are biased together by a spring clip so that the electrical contacts touch one another when the card is removed from between the electrical contacts.
U.S. Pat. No. 4,480,250 patented by C. D. McNeely Oct. 30, 1984 describes a wallet having an alarm circuit connected to a plurality of electrically and mechanically parallel metal clips and a printed circuit conductor line. Each clip independently closes mechanically and electrically on a printed circuit conductor line unless the closing is prevented by an intervening credit card in the clip. A single closing of the parallel circuits is sufficient to activate the alarm circuit.
U.S. Pat. No. 4,652,865 patented by A. Maharshak on Mar. 24, 1987 describes a plurality of pockets in which each pocket has conductive disks on the pocket walls at the center of each inner side of the pocket so that they contact when the card is removed from the pocket. One of the disks is magnetic so that the disks are drawn together.
In another embodiment electrical conductive areas on the pocket walls on the opposite inside surfaces of the pockets are biased toward one another by leaf springs inserted into the spaces between outer and inner layers of the walls of the pockets.
In another embodiment a pair of parallel conductive strips spaced from one another and parallel to the edge of the pocket opening traverse one inner face of the pocket. A longitudinal plate is positioned on the opposite inner face of the pocket so that it crosses both strips.
In another embodiment a single conductive strip extends approximately corner to corner of one inner face of the pocket the ends being spaced from the top and bottom of the pocket, and a single conductor strip extends approximately corner to corner of the opposite inner face of the pocket the ends being spaced from the top and bottom of the pocket, so that the conductors intersect at about the center of the pocket. The conductors pass through the seams of adjacent pockets so that the contact arrangement at the center of the pocket is in each pocket.
U.S. Pat. No. 4,890,094 patented Dec. 26, 1989 by D. Kopel describes a wallet structure in which the pockets are made from a long flexible dielectric sheet that is folded normal to the length of the sheet in a fan fold to form card accommodating compartments by various means including adhesive and/or stitching Preferably a decorative material such as leather is secured around the dielectric sheet and over its exposed edges.
A first conductive bus extends the length of a front surface of the sheet adjacent to one edge of the sheet. A second conductive bus extends the length of the front surface of the sheet adjacent to the other edge of the sheet, parallel to the first conductive bus. Each of the first and second busses continues over each fold normal to the fold and coincides with itself in each pocket formed by the folds.
Alternating conductive strips on the front surface extend from each conductive strip normal to the strip, separated by and spaced from fold lines of the accordion fold so that in each pocket a strip from the first conductive bus on one inner wall of a pocket contacts a strip from the second conductive bus on the opposite inner wall of the pocket at the center of the pocket. The contact activates an alarm. Contact is prevented by an intervening credit card in the pocket.
In order to assure contact between the strips in each pocket in the absence of a credit card between them, a plurality of resilient cushioning pads are secured to the rear surface of the dielectric sheet, one pad of the plurality of pads behind one of the conductive strips in each pocket.